A washing machine refers to an apparatus that eliminates foreign substances in, on or attached to laundry by agitating and rotating water, detergent and the laundry. Washing machines may be classified into pulsator type washing machines that wash the laundry using a water flow generated by operation of a pulsator in the washing tub, and drum type washing machines that wash laundry by dropping the laundry vertically, which is caused by rotation of the drum.
The drum type washing machine has a door at the front of the washing machine that allows the user to put the laundry through the door. The drum type washing machine operates in a manner that drops and washes the laundry, and uses relatively small amounts of water and detergent. Specifically, a drum type washing machine in the related art includes a cabinet that forms an external appearance of the washing machine, a tub that is installed in the cabinet and that stores water, a rotatable drum in the tub that holds or accommodates laundry, a drive motor that is installed behind and/or below the tub and that provides power to the drum, a water supply device that supplies water to the tub, and a drain device that discharges water in the tub to the outside of the cabinet after a washing operation ends.
Accordingly, in the drum type washing machine in the related art, when the laundry is washed, the laundry is put into the tub in a lateral direction by opening the door at the front of the washing machine, supplying water to the tub, and then washing the laundry while a lifter in the drum lifts up and drops the laundry by rotation of the drum, which receives rotational power from the drive motor.
As such, the drum type washing machine in the related art includes the tub in addition to a separate drum. That is, the drum type washing machine in the related art has a structure in which the tub stores water and the drum washes the laundry, wherein the drum is installed in the tub.
However, because the tub is typically made of a plastic material, the tub may be easily contaminated by mold, mildew, water scale or other foreign substances entering or generated in the tub when the tub is used over a long period of time. There is a problem in that it is difficult to clean the tub when the tub is contaminated because the drum cannot be easily removed. When the tub, which stores water, is contaminated, the tub may become corroded and then the laundry may become contaminated, which may cause a user to incur a skin irritation or disease.
This problem exists with the pulsator type washing machine as well as the drum type washing machine. The reason is that the pulsator type washing machine also includes a reservoir (tub) in a main body thereof.
According to the drum type washing machine in the related art, the drum rotates and is supported by a single shaft at a single side or end, and thus, there is also a problem in that vibration and noise may occur due to deflection(s) of the shaft.